linux-kernel - Re: [PATCH 3/7] PCI/PM: Clear PCIe PME Status even for legacy power management

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 15 Oct 2019 19:20:01 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Bjorn Helgaas <helgaas@...nel.org>
Cc:     Dexuan Cui <decui@...rosoft.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Michael Kelley <mikelley@...rosoft.com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        KY Srinivasan <kys@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>, olaf@...fle.de,
        apw@...onical.com, jasowang@...hat.com, vkuznets@...hat.com,
        marcelo.cerri@...onical.com, jackm@...lanox.com,
        linux-pci@...r.kernel.org, linux-hyperv@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        driverdev-devel@...uxdriverproject.org,
        Bjorn Helgaas <bhelgaas@...gle.com>
Subject: Re: [PATCH 3/7] PCI/PM: Clear PCIe PME Status even for legacy power management

On Tuesday, October 15, 2019 1:00:12 AM CEST Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@...gle.com>
> 
> Previously, pci_pm_resume_noirq() cleared the PME Status bit in the Root
> Status register only if the device had no driver or the driver did not
> implement legacy power management.  It should clear PME Status regardless
> of what sort of power management the driver supports, so do this before
> checking for legacy power management.
> 
> This affects Root Ports and Root Complex Event Collectors, for which the
> usual driver is the PCIe portdrv, which implements new power management, so
> this change is just on principle, not to fix any actual defects.
> 
> Fixes: a39bd851dccf ("PCI/PM: Clear PCIe PME Status bit in core, not PCIe port driver")
> Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>

This is a reasonable change in my view, so

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

> ---
>  drivers/pci/pci-driver.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index d4ac8ce8c1f9..0c3086793e4e 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -941,12 +941,11 @@ static int pci_pm_resume_noirq(struct device *dev)
>  		pci_pm_default_resume_early(pci_dev);
>  
>  	pci_fixup_device(pci_fixup_resume_early, pci_dev);
> +	pcie_pme_root_status_cleanup(pci_dev);
>  
>  	if (pci_has_legacy_pm_support(pci_dev))
>  		return pci_legacy_resume_early(dev);
>  
> -	pcie_pme_root_status_cleanup(pci_dev);
> -
>  	if (drv && drv->pm && drv->pm->resume_noirq)
>  		error = drv->pm->resume_noirq(dev);
>  
>